Oranges and grapefruit have been packaged in bags at the shipping point for more than three decades in Florida. For about 20 years it was all done manually. Only fabric mesh bags were used before polyethylene film bags, which first appeared in Florida statistics for the 1958-1959 season. Polyethylene net bags first appeared in Florida statistics for the 1966-67 season.
In Florida most citrus bagging in polyethylene film bags is done by semiautomatic machinery: limited automatic machines are in use. In all semiautomatic bagging operations, purchased (premanufactured) bags are used entirely. The semi-automatic equipment used by the larger portion of the packinghouse counts the desired quantity of fruit into the bag upon actuation of a foot pedal or other control by the operator. The operator holds the bag in position to catch the fruit, then closes it by a tape or stapling device, and places it in a master carton. Similar semiautomatic equipment is used elsewhere for packaging such produce as apples, onions, and potatoes in polyethylene film bags. Generally, this equipment measures quantity by weight instead of count. Machine action or the operator pours the measured quantity from a pan or accumulating chamber into the bag after the machine feed has stopped at a preset weight. Bag closing practices are similar to those employed on semiautomatic citrus bagging operations. Semiautomatic machines suitable for polyethylene film bags are also generally usable for bagging fruit in polyethylene net bags.
Automatic polyethylene film bagging machines have been installed in several Florida packinghouses over approximately the past three years. Premade bags are used by all of them except for one make that uses specially prepared film, doubled, in a ribbon with perforations in heat-sealed strips betweem bags. The bagging machine heat-seals the top after filling except where twist-tie or Kwik-lok closing has been substituted. Bags separate along perforation lines in passing out of the machine onto the takeaway conveyor. Manual checking of bag weight is required in operating one make of these machines, a carrousel type.
No fully automatic machines are available for handling polyethylene net bags except one type, recently offered in the Florida citrus area, with an attachment for automatically handling net bags supplied on wire frames. Thus far, the tooling of bagmakers has not provided for supplying polyethylene net bags in this way. Since manufactured polyethylene net bags cost about twice as much as film bags, there would be an economic as well as many other advantages accruing to consumers and packers alike by having bag forming incorporated into an automatic cycle of bag filling and closing machinery.
These concepts were emperically tested and evaluated by constructing an experimental machine. Testing of the machine was confined to packing 5-pound bags of oranges because of their lead in shipment of Florida citrus fruit in polyethylene net bags. The machine is adaptable, however, to other bag sizes, produce, and applications.